Signor of one-half to john jones williams



(Nq-Model.) l

Y R. M. PRIGHARD.

4'SURFAGING MACHINE'.

No. 395,631. Patentd Jan. l, 1889.

UNTTE STATES Trice..

PATENT RICHARD MORRIS PRIOHARD, OF

NEIV ROCKLAND, QUEBEC, CANADA, AS-

SIGNOR OF ONE-HALF TO JOHN J ONES VILLIAMS, OF SAME PLACE.

SURFAClNG-IVIACHINE.

SPECIFICATION forming part of Letters Patent No. 395,631, dated January 1, 1889. Application filed July 25, 1887. Serial No.245,209\ (No model.)

To all whom "t may concern:

Be itknown that I, RICHARD MORRIS Pinon- ARD, machinist, of New Rockland, in the county of Richmond and Province of Quebec, Canada, have invented certain new and useful Improvements in Slate-Surfacing Machines; and I do hereby declare that thc following is a full, clear, and exact description of the same.

This invention has reference to apparatus for smoothing and polishing the surfaces of school-slatcs, which operation heretofore has been performed either by hand or by driving the slates between two abrading-rollers, at a great loss from breakage, &c.

The invention embraces an arrangement whereby water is introduced between the grinding-surface and the material being operated upon at a central point, from which it is driven outwardly, so as to keep the material free from dirt and allow the grinder to work more effectively upon it. This arrangement consists in having' the revolving' shaft on the end of which the grinder is secured made hollow, so that water run into it from any convenient source will pass through a central aperture in the grinding-disk and be spread centrifugally by the revolution of the same.

Other features are, first, the mann er in which the grinder is secured tothe end of the revolving shaft, and, secondly, a revolving endless Jtable for carrying the slates under the grinder, this table being washed at a point in its revolution, so as to be in a clean condition to receive the slates. L

The grinder is secured to the end of the shaft in the following manner: On the end of the shaft is screwed a flat metal disk, against the outer face of which the annular grinder, of the required material, is held by a metal ring of greater diameter, clipping ils depressed outer edge, and secured to the disk by suitable screws, dsc., outside grinder.

The table for carrying the slates may be described as an endless chain of carriers linked together and carried over two hexagonal drums provided with teeth to fit the links, one of which is operated from the main shaft through any suitable mechanism. These carriers, after disposing of the slates, pass through a trough of water arranged under the machine.

For full comprehension, however, of the invention reference must be had to the annexed drawings, in which- Figure l is an end view ofmy machine; Fig. 2, a longitudinal vertical sectional elevation of same on line X X, Fig. l. Fig. 3 is a vertical section of grinder secured to end of hollow shaft; Fig. 4, a bottom view of same, and Fig. 5 a transverse section of one of the carriers of the revolving table.

Similar letters of reference indicate like parts.

AA are suitable side frames, with horizontal guides a a formed on their inner sides for the endless table, to be hereinafter described, to work on, and connected transversely by cross-pieces A2 A3, in which are :formed bearings for the vert-ical hollow shaft B. On this shaft B is carried a cup, B', on its upper end, into which is led the end of a suitable watersupply pipe; a cone-pulley, B2, from which the drums carrying the endless table are to be operated, as will be hereinafter described; a main pulley, B3, to receive a belt from any operating mechanism, and a clutch-collar, B4, connected with an adjusting device, to be hereinafter described, for adjusting the shaft and with it the grinder O, secured to its lower end. The shape of this grinder and manner of securing it to the lower end of the shaft B will now be described. The grinder, as shown in section in Fig. 3, is a fiat annular disk, C, of the required material, having a central opening, C.

D is a iiat metal disk, with a collar, D', formed on its upper side, by which it is screwed upon the lower end of shaft B, which is also threaded to receive it up as far as the rigid collar L on the shaft.

E is a metal ring arranged concent-rically with the grinder-disk O and upon the depressed annular surface 02, and secured to the disk D by screws e, so as to hold the grinderdisk firmly between it and the face of the disk D, and in case it should break at any time prevent the parts from iiying out.

F F are the slate-carriers, preferably formed of thin pieces of metal of suitable size, perfo- IOO rated, as shown in Fig. 5, to allow dust and dirt to fall through, and having eyes F' F' formed at each end, so that a number of them can be hinged together by means of pins F2, passed through the eyes F' F' in the usual way, and when so connected form an endless band. These plates F F are provided with `slight depressions or seats F3 on their upperI sides, in which the slates may rest.

G G are double links extending' along both sides of each alternate carrier, through the ends of which and those of the single links G G', extending along the sides of the otherearriers, the ends of the pins Fzalso pass, and are then headed to hold all together in the usual way.

H H' are hexagonal drums mounted on shafts H2 H3, carried in bearings formed in the side frames, A A', and having teeth or projections h 7L', formed on three alternate sides, which lit the double links G G, connected with the carriers. rlhc shaft H2 has a gear, I, mounted on one end, which is turned by the worm on shaft J, carried in suitable bearings from side frame, A, and revolved by means of a band, J', taken from the cone-pulley B2 over roller A4, mounted on the top of side frame, A, to another cone-pulley, I2, on the worin-shaft J. I

K is the water-trough placed between the side frames, A A', and extending the full length of the maehine.

The adjusting device before mentioned consists of a lever, L, forked at one end to lit and be pivoted to the loose collar B, held in place on the shaft l between two rigid collars, b b. rlhis lever is fulcrumed to the standard Z from cross-piece A3, and used to raise or lower the shaft ll, and with it the grinder C, for operation on different thicknesses of material. A set-screw, L', is carried in a projection from the side frame, A'

to keep the lever L in the desired position,

and when any unevenness in the material occurs, tending to raise the shaft, it free to rise, and is prevented from too sudden a return by the coiled spring M acting upon the outer end of the lever to ease it down.

The operation is as follows: The shaft B is revolved at a high rate of speed, and from the cone-pulley B2, through belt J' and conepulley J? on worm-shaft J a slower motion is imparted to the drum Il by the gear I on its shaft intermeshin g with the worm on shaft J. The teeth on this drum [it in the double links G G and work the endless band of carriers, which bears, when under the grinder, on'the guides a ci, in the side frames, and is made of su ftieient length to allow a certain amount of slack to drag through the water-trough K. The slates X are laid on the carriers at one end of the machine, and taken by them under the grinder-disk C, where one side will be surfaced or polished, and thence to the other end of the machine, where they are removed from the carriers in any convenient n'ianner, and, to save time, taken to another similar machine to have the other side surfaced.

It will be seen that the water descending the hollow shaft B will be spread centrifugally, so that all dirt and dust will, be thrown outward and off the slates being ground.

The number of grin din g-disks in a machine is not confined to one, as more can be employed according to the purpose for which it is designed, and they may be ot' different material and abrading quality.

lVhat I claim is as follows:

In a school-slate-surfacing machine, the combination of a vertical hollow revolving shaft adapted to be rotated by any suitable means, frame of machine having suitable bearings for sueh shaft, an annular grinder rigidly secured on end of said shaft and revolving with it, the endless band of planesurfaee slate-carriers for carrying the slates under the grinder, supports for such endless band while passing under said grinder, drums adapted to be rotated by any suitable means for operating such band, and a water-trough through which such endless band passes, as set forth.

Dated at Richmond, Quebec, this llth day of July, 1887.

RICHARD MORRIS PRICHARD.

In presence oit- HARVEY V. BROWN, GEORGE KINCH. 

